course PHY 201 PHY 201 Clarence Allan Gilbert Randomized Problem 1 Assignment 2 If the velocity of the object changes from 4 cm / sec to 16 cm / sec in 8 seconds, then at what average rate is the velocity changing? To find the average rate at which the velocity is changing we find the average of the beginning and ending velocity (16 + 4 = 20/2 = 10 cm/sec) and divide it by the time interval over which this change was made (8 seconds). So the average change in velocity will be 10 cm/sec/ 8 sec= 1.25 cm/sec/sec A ball rolling from rest down a constant incline requires 8.2 seconds to roll the 97 centimeter length of the incline. What is its average velocity? The aveage velocity will be the dictance traveled divided by the time it took to travel that distance so the avearage velocity of this ball is 97cm / 8.2 cm=11.82926829 or 11.8 cm/sec to three significant figures. An object which accelerates uniformly from rest will attain a final velocity which is double its average velocity. What therefore is the final velocity of this ball? The final velocity of the ball will be 11.8 cm/sec *2 = 23.7 cm/sec.(If you multiply 2 times the average velocity and not the rounded value and then round the answer to 3 significant figures. What average rate is the velocity of the ball therefore changing? From beginning velocity of 0 to final velocity of 23.7 cm/sec over 8.2 seconds the ball has a average change in velocity (change in velocity / time interval) of 23.7 cm/sec /8.2 sec= 2.9 cm/sec/sec. An automobile accelerates uniformly down a constant incline, starting from rest. It requires 10 seconds to cover a distance of 132 meters. At what average rate is the velocity of the automobile therefore changing? The average velocity of the vehicle will be 132 meters /10 sec=13.2 meters/sec. So the final velocity of the vehicle is 26.4 meters/sec. The chance in velocity is going to be 26.4-0= 26.4 meters/sec divided by the time of 10 seconds will give you an average change in velocity of 2.64 meters/sec/sec "